Uniform strand tension device



Feb. 19, 1952 J. A. TRUITT UNIFORM STRAND TENSION DEVICE Filed Jan. 25, 1951 INVENTOR. dodEPH A. TRU/ T7 ATTORNEK Patented Feb. 19, 1952 UNIFORM STRAND TENSION DEVICE Joseph A. Truitt, West Chester, Pa., assignor to American Viscose Corporation, Wilmington, Del., a corporation of Delaware Application January 23, 1951, Serial No. 207,346

8 Claims. 1

This invention relates to mechanism for regulating the size and contour of a balloon and the tension in the strands passing through this balloon to a strand doubling unit from the supply sources.

It is an object of the present invention to provide cord-twisting apparatus capable of continuous operation free of trouble arising from variable strand tensions. It is also an object to provide a cord twister of the down-twisting type which operates with a stable balloon. Still another object is to provide cord-twisting apparatus for doublers of the down-twisting type which automatically controls, by self-compensating means, the strand tension within the balloon formed around the doubler as the strand passes thereinto. Other objects, features and advantages will be apparent from the following description, of the invention and the drawing relating thereto in which Fig. 1 is a diagrammatic view in elevation o doubling apparatus having an adjustable automatically compensating tension control system;

Fig. 2 is a fragmentary section view taken along line II-II of Fig. 1;

Fig. 3 is a diagrammatic pictorial view of a modified tension-controlling system;

Fig. 3a is a fragmentary diagrammatic pictorial view of a modification of the system shown in Fig. 3; i

Fig. 4 is a section view of the another modified tension-controlling system;

Fig. 5 is a section view of the apparatus of Fig. 4 taken along line V-V.

Fig. 6 is a diagrammatic pictorial view of a third modification of a tension-controlling system;

Fig. '7 is a diagrammatic pictorial view of a fourth modification of a tension-controlling system;

Fig. 8 is a diagrammatic pictorial view of a fifth modification of a tension-controlling system; and

Fig. 9 is a view partlyin section of a portion of the apparatus shown in Fig. 8.

To accomplish the above stated objects and others ancillary thereto, cord twisting apparatus is provided comprising supply sources for a plurality of strands, a doubler of the down-twister type having a strand-drawing device for positively engaging the strand which is driven in synchronism with and by the drive means for 2 latter mechanism comprises a gathering roll or pulley driven by the strand group and an automatically adjustable system for controlling and restraining the rotation of the roll, or other rotatable strand-gathering member, which is inversely responsive to the tension in the strand group traversing a balloon formed around the doubler, i. e. the greater the tension, the less is the restraint exerted on the rotation of the roll. Fig. 1 diagrammatically illustrates a doubling system comprising up-twisting type singles twisters 8 and I, a down-twisting type doubler 8, guides 9, 18, H mounted axially over twisters 6, I and 8, respectively, to define the upper limitation of the balloon in the strand associated with each twister, and an automatic or self-compensating tension device. The initial tension in the individual supply strands l4 and I5 passing from their respective singles twisters is established by tension devices It and I1, respectively mounted over, or supported by, packages being unwound while supported on the singles twisters. The strand I4 is led through the device 16 in being unwound from the package iii. The strand passes downwardly through a hollow spindle 28, out a lateral opening 2|, over the periphery of a flyer 22, and upwardly through the guide 9. The strand l5 traverses a similar path. Both singles strands pass onto an annular surface 25 of a gathering roll 26 to be wrapped therearound and discharged as a strand group hereinafter referred to as strand 28. The strands l4 and I5 are preferably wrapped or lapped around the surface 25 to the extent of one or more windings to provide sufficient frictional engagement between the strands and the surface 25 to prevent slippage as the result of any difference between (a) the aggregate tension in the strands received by the surface 25 and (b) the tension in the strand 28 discharged therefrom. It is for the utilization of this difference in tension that this invention is designed in order to control and maintain a substantially uniform tension in the strand within the balloon of the the doubler, and mechanism for receiving the plurality of strands, gathering them into a group, and discharging them toward the doubler. This doubler 8. In a doubling system wherein-the aggregate tension in fihe strands passing from the supply sources to the gathering mechanism exceeds that in the doubledstrand passing into the doubler, the strands may be fed to the gathering mechanism, or the gathering roll or rotor thereof may be connected with a driving means. Normally, however, the tension in the doubled strand exceeds that of the sum of the tensions in the supply strands, and the gathering roll operates as an idler being driven merely by the strands wrapped therearound. The embodiments of this invention are hereinafter described with respect to this latter condition.

The strand 26. as well as the strands I6 and i6 which constitute the larger strand 26, are pulled through the doubling system by means such as a pair of capstan rolls l6 and II rotatably mounted on a cage 62. The cage as well as a package holder 66 are rotatably mounted on the hollow spindle 54 of the doubler. The cage, however, is held from rotation by being weighted on one side (the spindle being in this csae inclined) or optionally by a stationary magnetic holding device (not shown) mounted exteriorly of the balloon in strand 26, such as is well known in the art; the package holder, on the other hand, is driven by the spindle through a slip-drive transmission, such as a magnetic clutch 66 having a driving member attached to the spindle and a driven member attached to the holder. The strand 26 is guided onto a package 66 by a reciprocating guide 66 which traverses an elongate member 46 extending longitudinally of the cage 62. Any well-known arrangement for traversing the guide 66 may be used. For example, the guide may be mounted on the member 46 which may comprise a reverse threaded rod in threaded relationship with the guide 36 and be rotated by a pawl-and-ratchet system driven by a cam surface disposed along an annular surface of the package holder, such as illustrated in application Serial No. 93,939, filed May 18, 1949. The twisting units 6, I and 6 may be driven by hydraulic motors 42, 46 and 66, respectively, such as described in U. S. Patent 2,546,936, December 4, 1951, or by individual electrical motors, or connected together in drive relationship by gears or belts and pulleys.

It is very desirable to control the tension and the contour of the'balloon of the strand 26 as it passes from the guide ll into the doubler 6 in order that the quality of the doubled strand may be satisfactory and that the doubler system may be operated without shutdowns as the result of the balloon getting out of control and the strand becoming subsequently fouled in the machine. To obtain a balloon of adesired contour, it is merely necessary to control the tension in the strand 28 so as to maintain it at a substantially uniform value. Heretofore, in strand doubling practice, it was extremely difllcult to maintain a uniform tension in the strand passing to a doubling-unit because of, for example, the variations of tension occurring in the strands being supplied to the unit or in the doubled strand being withdrawn from the balloon. However, in the practice of the present invention, the several strands of the group being twisted into a cord are first passed around the gathering roll 26 of Fig. 1. The rotation of the roll 26 is controlled in a manner such as to produce substantially uniform tension in the strand group after leaving said roll.

The gathering roll 26 constitutes the portion of the adjustable self-compensating tension control device 56. It constitutes also a portion of a rotor comprising also a cylindrical braking surface 52. The rotor comprising the roll 25 and the surface 52 is freely rotatable with respect to a fixed axis 53 except for the retardation exerted by a brake means connected with a lever 56, such as a rope or strap brake similar to that shown in Fig. 3a and hereinafter described, or the brake shoe 55 shown in engagement with the surface 52. The lever 56 is pivotablv supported above, and transversely of, the axis 53 from a stationary bracket 58 by a pivot 56. The pulley 66 is rotatably supported on lever 56 at 62 on the side of the pivot 56 opposite the portion of the lever which urges the shoe 56 toward the drum 52. A spring 64 is connected with a portion of the lever 56 on the side of the portion connected with the shoe 56 opposite the pivotable support for the lever 56. The other end of the spring 64 is anchored to a stationary threaded element 65 by a nut 61 providing adjustability of the extension of the spring to increase or decrease its pull on the lever 56. A dash pct 16 may be provided, if desired, to dampen the movements of the lever.

The upwardly-extending shank portion of the brake shoe member 55 is bifurcate as shown in Fig. 2 to provide a slot ll through which the lever 56 extends. The legs of the shank portion are supported slidably between a, pair of pins 12 and 13 secured to, and extending through, the lever 56. A spring 16 is held under compression between the undersurface of the lever and the bottom surface of the slot II to urge the two surfaces apart. In this manner, the movement of the lever 56 toward and away from the brake surface 52 is translated into variations in the pressure with which the brake shoe member 55 engages the surface 52.

In operation, an increase in tension in the strand 26 produces a downward movement of the pulley 60 and raises the portion of the lever 56 on the opposite side of the pivot 56. The upward movement in the portion of the lever 56 at the right as seen in Fig. 1 is resisted by the tension spring 66. However, such upward movement partly relieves the pressure of engagement of the brake shoe 55 with the rotor surface 52 in proportion to the magnitude of the movement as the undersurface of the lever tends to move away from the spring 16. The rotor turns with greater freedom as the brake shoe pressure is decreased permitting freer passage of the strand toward the doubler 6 and reduction in the tension thereof. Conversely. a reduction in tension in the strand 26 below the tension therein needed to maintain a desirable balloon contour in the strand 26 results in an upward movement of the pulley 66 and depression of the portion of the lever 56 on the opposite side of the pivot 56. The lever compresses the spring 16 which urges the shoe member 55 against the surface 52 at greater pressure. The rotation of the gathering roll 25 is thus restrained; as the strand is advanced through the doubler 6 at a substantially constant rate by the capstan rolls 66 and 6|, and the tension in the strand 26 passing through the balloon formed around the doubler-is increased. Although the device 56 is diagrammatically illustrated, it is obvious that a great many variations are possible in the lengths of the lever arms and the spring tensions employed. By proper adjustment, the device 56 may be adjusted to control the tension in the strand 26 within a desired working range.

Fig. 3 illustrates the device 60 that may be used in place of device 56 of Fig. l to automatically control the tension in the strand 26. The smaller strands l4 and I5 which comprise the strand 26 are gathered on a roll 62 which is fixed on a shaft 66 which supports also a brake drum 64. The shaft 66 is supported on a fixed axis by a bearing 65. A pulley 66 is rotatably supported at one end of the lever 61 by a stationary bracket 66. Downward movement of the portion of the lever 61 adjacent the pulley 66 relative to its pivot axis at 66 is resisted by a spring 9| attached by one end to the lever and by its other end to a nut 66 in adjustable threaded relationship with an element 92. Another lever 95. notched at 89.

to receive the lever 81, extends laterally over the brake drum 84 into attachment with a spring 91 secured to a stationary anchor comprising a threaded element 98 and a nut 99. A brake shoe member IOI is supported in slidable resilient engagement with the lever 95 and engages the brake surface 84. The lever 95 is pivotably supported by a stationary clevis I03 attached thereto by a pivot pin I04 to a portion of the lever spaced between the notch 98 and a portion of the lever immedi tely under the brake drum 84. The lever 95 extends through a slot I06 formed by a bifurcated portion of a brake shoe member IN. The lever 95 is slidable within the slot in a direction lateral with respect to itself. A spring I09 is positioned within the slot between the bottom thereof and the undersurface of the lever to convert movements of the lever into variations of pressure with which the shoe engages the drum 84. The brake shoe member IOI is positioned slidably between pins H and III which prevent movement of the member IOI in a longitudinal direction along the lever 95. Although the lever 95, as illustrated, is used to operate a shoe-type brake, it may be utilized by suitable connections to apply other types of friction elements to the surface 84, such as a band or' rope brake. The brake system of Fig. 3 may be replaced as shown in Fig. 3a wherein a flexible member II2 of rope, a band of leather or other flexible material H2 is substituted for the shoe IOI. One portion of the band is fastened to a stationary bracket H3 and another portion is fastened to a bracket H4 mounted on the arm 95; an intermediate section of the band II2 engages the periphery of the drum 84. The arms .81 and 95 move as they do in the embodiment illustrated in Fig. 3 to produce changes in the braking force applied to the drum 84.

In operation, an increase in tension in the strand 28 produces a downward movement of the pulley 86. As the lever 81 swings downwardly with respect to its pivot 89, it carries with it the notched end of the lever 95 which tilts about the pivot axis at I04. The end of the lever 95 to which the spring 91 is attached moves upwardly to extend the spring; thus downward movement of the pulley 881s resisted by the springs 9| and 91. Although the portion of the lever immediately over the drum 84 moves away from the drum, the brake shoe IOI remains in contact with the drum 84 as a result of the expansion of the spring I09. The pressure of the shoe against the drum. however, becomes lessened as the spring I09 becomes extended. As the brake shoe pressure is lessened, the assembly comprising the drum 84, shaft 83 and the gathering roll 82 is permitted to rotate with less restraint and the increase in tension in the strand 28 which initiated the operation of the device is relieved. The actuation of various portions of the device 80 is reversed when the tension in the strand 28 drops below the average control tension to which the device is adjusted.

Figs. 4 and 5 illustrate an alternative device II5 which may be used to automatically control the tension in the yarn 28 in lieu of the devices and 00 of Figs. 1 and 2, respectively. This device comprises a container II6, a shaft II1 extending therethrough and exteriorly thereof to support a gathering roll H8 fixed to the shaft.

Interiorly of the container Hi, the shaft supports a plurality of discs I20 which are fixed to the shaft and spaced in parallel arrangement to receive a plurality of alternately spaced bifurcate plates I22 which may be moved in a vertical direction into interdigital relationship with the discs I20 to vary the degree of extension of the plates within the spaces between the discs. The plates I22 are connected together by a common support comprising the rod I23 and a yoke I24 having its separate legs attached to the rod. The yoke is attached by its upper end to a lever I26 on which a pulley I21 is rotatably mounted. The lever is pivotably supported at I52 above the container at a point between the pulley and the point of attachment for the yoke I24. The plates are bifurcated or slotted in the middle so that substantial sections thereof may be lowered below the level of shaft I I1 as shown in Fig. 5. The relative positions of the pulley I21 and the gathering roll I8 may be substantially similar to the relative positions roll 29 and the pulley 62 of Fig. 1, or roll 92 and pulley 86 of Fig. 2. A spring I30 is connected between a stationary anchor element HI and a portion of the lever I26 disposed between the pulley I21 and its pivotal support at I32. Strands from separate supply sources are gatheredon the roll I I8 and passed as a group over the roll I21 in the manner shown for the roll 25 and the pulley 60 of Fig. 1. larger strand or strand group comprising the supply strands passes from the pulley I21 toward a guide associated with the doubler, such as guide II of Fig.1.

In operation, an increase in tension of the strand group passing to the doubler moves the pulley I21 downwardly in opposition to the pull exerted by tension spring I30 and the weight of the assembly comprising the plates I22 and the supporting elements I23 and I24, as well as a portion of the lever I26 from which the assembly is suspended. A liquid is supported within the container I It at a level preferably over the upper portion of the rotatable discs I20. A liquid is selected which has such a viscosity that it exerts a drag on the discs when the plates I20 are completely removed between the discs and produces a tension of low magnitude in the strand group passing from the doubler which is well below the working range of tension within which it is desired to have the device II5 operate.

The discs I20 are spaced sufliciently close together so that there are small clearances between adjacent plates and discs when the plates are lowered between the discs, and substantial increases in drag will be produced as the plates I22 are progressively lowered between the discs I 20. Consequently, when the portion of the lever to which the yoke I24 is moved upwardly in response to an increase in the strand passing over the pulley I21, the plates I22 are lifted to an extent which is proportional to the downward force exerted on the pulley I21. As the plates I22 are raised relatively to the discs I20, the drag load resisting the rotation of the plates I20 and the gathering roll H8 is reduced and the tension is correspondingly relieved in strand 28 passing into the balloon formed in the strand around the doubler 8.

Conversely, a reduction in the tension of the strand passing to the doubler permits the pulley I21 to swing upwardly and the consequent lowering of the plates between the rotating discs increases the drag load applied thereto. The consequent restraint in the rotation of the pulley II8 produces an increase in tension in the strand group passing over the pulley until an equilibrium of forces is established within the device.

Fig. 6 is a diagrammatic pictorial represen- The 7 tatlon of a device I38 which may be used in place of the device 50. 80 and II! of Figs. 1, 3 and 4, respectively, in combination with the uptwisting units 6 and 1, and the doubling unit 8 of Fig. l. The device I35 comprises a gathering roll I36 fixed on a shaft I31 common to the v rotor I38 of a fluid motor I40. The rotor I38 is provided with radially extending blades I which revolve at close clearance with the housing of the motor. A fluid, preferably a liquid, passes into the motor I40 through a feed line I42 and is discharged through an exhaust line I43. The exhaust line I43 may be connected to a suitable reservoir (not shown) connected also with the supply line I42 '50 that the fluid passed to the motor I40 may be recirculated. The rotatable assembly comprising the strand-gathering roll I36, the shaft I31 and the rotor I38 is supported on a fixed axis by means such as a bearing I44. The rate of passage of fluid through the motor I40 determines the speed of operation. Passage of the liquid into the motor is controlled by a valve I41 provided with a control lever I48. The lever I48 is connected by a link I48 to a portion of the lever I50. A pulley I52 is rotatably supported by the lever I50 in a position above and laterally offset with respect to the strand-receiving surface of the gathering roll I36. The axes of the roll I36 and the pulley I52 are preferably substantially parallel. The lever I50 is pivotably supported by a stationary support member I54 at a portion of the lever between the portion thereof supporting the pulley I52 and the portion attached to the link I48. A spring I56 is connected to the lever I50 at a point between the pulley I52 and the axis of attachment of the lever to the support I54. The end of the sprin I56 is adjustably secured to a stationary element I51 by an element I58 which is adjustable lengthwise of the element I51.

The device I35 is actuated by an increase in tension in strand I28 in response to which the pulley I52 moves downwardly and the portion of the lever I50 disposed oppositely from the support I54 swings in an upward direction. The control element I48 of the valve I41 is moved upwardly to open the valve. The valve I41 is opened to an extent which is proportional to the movement of the pulley I52 and the lever I50. A proportional increase in the amount of fluid passing through the motor I40 lessens the retardation applied to the roll I36 through the shaft I31 by the motor I40. The gathering roll is driven, in accordance with this embodiment, by the strandwrapped therearound in a manner similar to that in which the analogous strandgathering rolls of the other embodiments herein described are driven. When the tension in the strand 28 drops below the desired average tension level, the actuation of the device I35 proceeds in a reverse manner to that just described to retard the rotation of the gathering roll I36 and to increase the tension to the average level.

Fig. 7 illustrates diagrammatically and pictorially another modified device that may be used to automatically control the tension in strand passing between strand supply sources and a doubling unit, such as illustrated in Fig. l. A rotatable assembly comprising a shaft I62, a gathering roll I63, and a brake drum I64 is secured to a shaft which is supported by a stationary bearing I65 to which the shaft extends. A brake shoe I61 is held in engagement with'the peripheral surface of the drum I64a compression spring I68 supported under compression between the brake shoe and a lever I68 having bifurcated end portions. The spring is supported laterally by a rod I10 in fixed attachment with the shoe I61 in slidable relationship with a bifurcate portion of the lever I68. The opposite bifurcate portion of the lever is pivotably secured to an extension of the solenoid plunger "I which moves into and out of a solenoid coil "la. The electrical power transmitted to the solenoid coil is adjustably controlled by a current regulator such as a rheostat I12 connected in series with a supply line I13 and one terminal of the coil. The other terminal of the coil may be connected directly as shown with a supply line I14. The control element I16 is connected by a link I11 in pivotable connection with both the lever I18 and the control element I16. A pulley I82 is supported by the lever at a position which is spaced above and laterally offset with respect to the strand-receiving surface of the gathering roll I63. The lever I19 is pivotably supported by a stationary bracket I84 at a point spaced between the pulley I82 and the point of connection of the lever with the link I11. A spring I85 is attached by one end to the lever I18 at a point between pulley I82 and pivotal connection of the lever with the bracket I84, whereby the pulley is urged upwardly in opposition to tension in the strand 28. The other end of the spring I85 is secured to an adjustable stationary mounting comprising an elongate element I88 and an element I89 which is adjustable lengthwise of the element I88 and attached to the end of the spring.

As in the other automatically adjustable tension devices herein described of which each has a lever analogous to the lever I19, an increase in tension of the strand 28 produces.downward movement of the pulley I82 and tilting of the lever I19. The rheostat I12 by being mechanically linked to the lever I18 is adjusted to a new setting effected by moving the control element I16 of the rheostat in a clockwise direction as viewed in Fig. 7. Movement of this element in a clockwise direction results in a corresponding reduction in the electrical energy transmitted to the solenoid coil. Such a reduction is accompanied by a movement of the solenoid plunger I1I toward the left out of the coil I1Ia. When this happens, the lever I68 swings on its pivot I68a to carry the bifurcate portion thereof in engagement with the spring I68 toward the right as viewed in Fig. 6. The spring I66 expands and partially relieves the pressure of the shoe I61 on the drum I64 with the result that the pulley I63 is permitted to rotate more freely. The tension in the strand of the balloon about the doubler is immediately and correspondingly reduced until a normal tension level is restored. A drop in tension below that desiredfor normal operation of the doubling system is accompanied by an upward movement of the pulley I82 and consequent adjustment of the rheostat I12 to increase the power supplied to the solenoid coil I18 from power supply lines I13 and I14. The plunger I1I is moved inwardly of the coil. By motion communicated through the lever I68, the pressure of the shoe I61 on the drum I64 is increased to retard the rotation of the gathering roll I63. The rate of passage of the strand 28 is reduced and the tension in the strand is increased until operating magnitude is obtained.

Fig. 8 depicts pictorially and diagrammatically another device I which may be used to receive and group strands passing from a plurality of supply sources and to discharge them as a group under substantially uniform tension toward a doubling unit. The separate strands I4 and I9 are received on a gathering roll I9I and discharged therefrom as a group constituting the strand 28 over a pulley I92 supported on a lever I93. The pulley and the lever are movable with respect to a pivot element I94 by which the lever is secured to a stationary support I96. Movement of the pulley I92 and the portion of the lever I93 adjacent thereto in a direction toward the guide II is resisted by a spring I98, one end of which is attached to a pin I99 extending laterally from the lever. The other end of the spring is attached to an element 200 which is adjustable lengthwise of an elongate mounting I. The gathering roll I9I is secured to a shaft 202 supported along a fixed axis by bearing 203. Secured also to the shaft is a rotor 205 comprising a magnetically-sensitive material. As shown in Fig. 8, the rotor 205 rotates in axially-spaced relationship with a stator 206 comprising a coil for producing a magnetic field in the region occupied by the rotor 205. The coil of the stator is energized through lines 208 and 209 connected with an electrical power source which is preferably held substantially constant. The stator is supported on a non-rotatable shaft 2 which may slide in an axial direction through the bearings 2I2 and 2I3. A pin 2|5 extending from the stator in a direction parallel with the shaft 2 is slidable with respect to a complementary bore 2"; in the bearing 2I2 to prevent rotation of the stator and the shaft 2| I. The shaft 2 is provided with threaded 2I8 on the portion thereof shown between the bearings 2 I2 and 2 I3. A spur gear 2 I9 having an interiorly-threaded hub-portion is supported on the complementary threaded portion of the shaft. The movement of the gear 2 I9 in a direction parallel to the shaft 2 II is prevented by base detent structure 22 I having spaced portions between which the gear rotates without simultaneous engagement of both portions. The teeth of the spur gear are engaged by a member 222 having a segmental gear portion 223. The member 222 is pivotably attached on the stationary mounting 224 by a pivotal element 225. The portion of the element 222' on the side of its pivot axis opposite the gear portion 223 is secured to a link 228 by a joint having universal action, such as the ball-and-socket joint 229 illustrated. The link 228 is connected to the lever I93 by another ball-and-socket joint 230.

The device I90 eifects control of the tension in the strand 28 within a narrow range. An increase of tension in the strand 28 results in movement of the pulley I92 and the portion of the lever I93 toward the guide II in opposition to force exerted by the spring I98. The end of the member I22 linked to the lever I93 moves upwardly in a clockwise direction with respect to the pivot 225. The segmental gear portion 223 in mesh with the gear 2I9 also moves clockwise. The gear 2 I 9 moves counterclockwise as indicated by the arrow. Thethreaded hub of the gear 2 I9 acting on the threads 2I8 of the shaft 2 traverses the shaft in a direction toward the right as shown in Fig. 8. The stator 206, carried by the shaft, is moved away from the rotor 205 with consequent weakening of the magnetic field in which the rotor turns. The drag load imposed on the rotor 205, the shaft 202 and the gathering roll I9I by the stator is reduced and the assemly turns more f v- The stran 2 moves toward the doubler with less restraint and the tension therein decreases to the normal magnitude for which the device I is adjusted. By a reverse procedure, the stator 206 is moved toward the rotor 205 to decrease the spacing therebetween and to increase the strength of the magnetic field acting on the rotor when the tension in'strand 28 drops below the normal operating tension of the doubler system. The device I90 in this manner automatically controls the tension of strand passing into the doubling unit of a cord-twisting machine, and may be constructed and adjusted to maintain the tension of the strand within a narrow working range.

While preferred embodiments of the invention have been shown and described, it is to be understood that changes and variations may be made without departing from the spirit and scope of the invention as defined in the appended claims'.\

1. Cord twisting apparatus comprising supply sources for a plurality of strands, a doubler having take-up means for positively engaging a strand material, drive means for the doubler, said take-up means being connected in positive drive relationship with the drive means, a stationary strand guide mounted in spaced axial relationship with the doubler and an adjustable automatically compensating tension-controlling mechanism for receiving the plurality of strands, gathering them into a group, and discharging the group toward and through the guide, the mechanism comprising a gathering roll supported on a fixed axis of rotation, a pulley, a lever for supporting the pulley movably along an ambit extending toward and away from the guide and rotatably on an axis generally parallel with the axis of rotation of the gathering roll, said ambit being spaced laterally from the strand-supporting surface of the gathering roll, means for pivotably supporting the lever attached to a portion thereof spaced from the portion which supports the pulley, means for restraining the rotation of the gathering roll, control means connected with the restraining means for actuating the restraining means to increase or decrease the rotation of the roll, said control means being connected with the lever, and responsive to movement of the lever corresponding to movement of the pulley away from the guide in proportion to the magnitude of said movements, to actuate the restraining means to restrain the rotation of the pulley, and adjustable resilient means for urging the lever in the direction about its pivot corresponding to movement of the pulley away from the guide.

2. Cord twisting apparatus comprising supply sources for a plurality of strands, a doubler having take-up means for positively engaging a strand material, drive means for the doubler, said take-up means being connected in positive drive relationship with the drive means, a stationary strand guide mounted in spaced axial relationship with the doubler and 'an adjustable selfcompensating tension-controllin mechanism for receiving the plurality of strands, gathering them into a group, and discharging the group toward and through the guide, the mechanism comprising a gathering roll, a brakedrum, a shaft having a fixed axis, said roll and drum being fixed to the shaft for rotation together, a lever, stationary means for pivotably supporting the lever in transverse and spaced relationship with respect to the drum surface and the axis of rotation thereof,

15 said lever being supported alon an intermediate I! portion thereof offset surface, a brake shoe member in engagement with a portion of the drum surface facing the lever, resilient means mounted between the brake shoe member and the lever for urging the brake shoe member toward the drum, a pulley rotatably supported on the lever on an axis extending generally parallel to the axis of rotation of the roll, said pulley being supported by the lever along an ambit extending toward, and away from, the guide, said ambit being spaced laterally in the strand-supporting surface of the roll, and adjustable resilient means in engagement with the lever to urge the portion thereof facin directly toward the drum in a direction toward the drum.

3. Cord twisting apparatus comprising supply sources for a plurality of strands, a doubler having take-up means ,for positively engaging a strand material, drive means for the doubler, said take-up means being connected in positive drive relationship with the drive means, a stationary strand guide mounted in spaced axial relationship with the doubler and an adlustable self-compensating tension-controlling mechanism for receiving the plurality of strands, gathering them into a group, and discharging the group toward and through the guide, the mechanism comprising a gathering roll for receiving the strands, a brake drum, a shaft supported along a fixed axis of rotation, the roll and the drum being supported on, and fixed to, the shaft for rotation together, a pulley, a lever rotatably supporting the pulley on an axis generally parallel to the axis of rotation of the roll and along an ambit extending toward and away from, the guide, said ambit being spaced laterally from the strand-supporting surface of the roll, stationary means spaced from the guide for supporting the lever, resilient means connected with the lever for urging it in a direction to carry the pulley away from the guide, a second lever extending laterally of the longitudinal direction of the firstnamed lever, said second lever engaging the undersurface of the first-named lever at a point spaced between the pulley and the stationary support, stationary means for pivotally supporting the second lever in connection with a portion thereof spaced between the first lever and a portionof the second lever nearest the shaft axis, a brake shoe member in engagement with the drum, resilient means supported between, and in engagement with the second lever and the brake shoe member, for urging the member toward the drum, and adjustable resilient means for urging the second lever toward the drum.

4. Cord twisting apparatus comprising supply sources for a plurality of strands, a doubler having take-up means for positively engaging a strand material, drive means for the doubler, said take-up means being connected in positive drive relationship with the drive means, a stationary strand guide mounted'in spaced axial relationship with the doubler and an adjustable self-compensating tension-controlling mechanism for receiving the plurality of strands, gathering them into a group, and discharging the group toward and through the guide, the mechanism comprising a container, a rotatable shaft supported within the container, a plurality of spaced discs supported coaxially on said shaft within the container, a gathering roll rotatably supported outside the container, means for connecting the roll and the shaft in positive drive relationship, a lever, stationary means for pivotably supporting the lever by an intermediate with respect-to the drum portion thereof above the container, a pulley rotatably supported by a portion of the lever spaced from its connection with the support means and spaced laterally with respect to the strand gathering roll on an axis substantially parallel to that of the roll, a plurality of plate members, means attached to an edge of each of the plate members for supporting them in a spaced parallel relationship similar to the spacing of the discs, support means attached to a portion of the lever further from the pulley than the support means of thelever for suspending the plate members in vertical alignment within the container with at least portions of the members extending in interdigital relationship between the discs, a liquid supported within the container at a level such that the discs are substantially submerged when the plate members are positioned at the lowest portion of their vertical ambit, and adjustable resilient means in engagement with the lever for urgin the lever in a direction to carry the gathering roll away from the guide.

5. Cord twisting apparatus comprising supply sources for a plurality of strands, a doubler having take-up means for positively engaging a strand material, drive means for the doubler, said. take-up means being connected in positive drive relationship with the drive means, a stationary strand guide mounted in spaced axial relationship with the doubler and an adjustable automatically compensating tension-controlling mechanism for receiving the plurality of strands, gathering them into a group, and discharging the group toward and through the guide, the mechanism comprising a gathering roll, a fluid motor having a rotor and a casing, the casing having an inlet port and an outlet port, said rotor having radially extending blades extending into close clearance with the interior surface of the casing, a shaft supported on a fixed axis. said rotor and the roll being fixed tothe shaft for rotation together, a fluid supply line connected with the inlet port of the motor, a valve in the supply line having a control element, a pulley, a lever for rotatably supportin the pulley on an axis generally parallel to the axis of rotation of the roll and along an ambit extending toward, and away from, the guide, said ambit spaced laterally from the strand-supporting surface of the roll, stationary means for pivotably supporting the lever and attached to a portion thereof spaced from the pulley, link means extending between a portion of the lever which is further away from the pulley than the portion connected with the support means for the lever, said link means being connected with the control element of the valve to increase the amount of liquid passing into the motor when the lever moves in a direction about its pivot corresponding to movement of the pulley toward the guide, and adjustable resilient means in engagement with the lever for urging the gathering roll mounted thereon in a direction away from the guide.

6. Cord twisting apparatus comprising supply sources for a plurality of strands, a doubler having take-up means for positively engaging a strand material, drive means for the doubler, said take-up means being connected in positive drive relationship with the drive'means, a stationary strand guide mounted in spaced axial relationship with the doubler and an adjustable automatically compensating tension controlling mechanism for receiving the plurality of strands, gathering them into a group, and discharging aasams rotatably supporting the pulley on an axis generally parallel to the axis of rotation of the roll and along an ambit extending toward, and away from, the guide, said ambit spaced laterally from th strand-supporting surface of the roll, stationary means for pivotally supporting the lever, and being connected to an intermediate portion of the lever, an electrical current supply means, a current-regulating means having a movable control element, said supply means, current-regulating means, and solenoid coil means being connected in series, and link means connecting the lever and the control element to effect a reduction in the power transmitted to the solenoid through movement of the lever in response to an increase in tension in the strand passing over the pulley.

7. Cord twisting apparatus comprising supply sources for a plurality of strands, a doubler having take-up means for positively engaging a strand material, drive means for the doubler, said take-up means being connected in positive drive relationship with the drive means, a stationary strand guide mounted in spaced axial relationship with the doubler and an automatically adjustable tension-controlling mechanism for receiving the plurality of strands, gathering them into a group, and discharging the group toward and through the guide, the mechanism comprising a gathering roll, an electromagneticallysensitive rotor, the rotor and the roll fixed to the shaft for rotation together, a stator mounted in axially opposed relationship with the rotor on a stationary shaft in substantially parallel alignment with the rotary shaft, said stator comprising an electromagnetic unit, bearing means for supporting the stationary shaft for holding said shaft and stator from rotating, said stationary shaft having an exposed threaded portion, an externally 14 toothed gear having an interiorly threaded hub portion in threaded relationship with the threaded portion of the stationary shaft, detent means for preventing movement of the gear in an axial direction, an externally toothed gear member supported on an axis parallel to the stationary shaft axis in mesh with the gear, a pulley, a lever for rotatably supporting the pulley on an axis generally parallel to the axis of rotation of the roll, said pulley being supported along an ambit extending toward, and away from, the guide, said ambit spaced laterally from the strandsupporting surface of the roll, support means being connected to a portion of the lever spaced from the pulley, link means connectin a portion of the gear member spaced from its axis to a portion of the lever spaced from the pivotable axis of the lever, said gear being rotatable in a direction to increase the clearance between the rotor and the stator when the lever is moved in a direction corresponding to movement of the pulley toward the guide, and resilient means connected with the lever for urging it in a. direction to carry the pulley away from the guide.

8. A system for doubling a plurality of strands into a cord comprising a plurality of strand supplies, means for doubling the strands and collecting the cord, means mounted on the takeup twister for drawing the strands from the supplies through the doubling position and then the cord through the balloon of the take-up twister, and a tension device for engaging the strands between the supplies and the take-up twister, said device comprising a rotatable memher around which the strands pass and are discharged as a group, a brake for controlling the rotation of the member, a tension-sensitive pulley for engaging the strand group, means connected with the pulley for actuating the brake to restrain the passage of the strands around the member in inverse proportion to the response of the pulley to the tension in the cord between the device and the twister, and adjustable resilient means for urging the pulley against the strand group.

JOSEPH A. TRUITT.

No references cited. 

